I avoided Trader Joes for years because I assumed it was over-priced health nut stuff. And it is. There is definitely some over priced stuff, and lots of health-but stuff.
But a lot of the food at Trader Joes is priced relatively close to what you'd pay at the grocery store. A lot of it can't be compared, however, because they have so many unique things. The next time you come across an ingredient in a recipe that you have no idea where to find, head up to Trader Joes. They have it.
The other great find here is the frozen meals. It's expensive, but these frozen meals are good. Really good. And good for you. They don't load them with salt and fat and sugar as with most processed meals.